Question

A force of 64 dynes is inclined to the horizontal at an angle of 60${}^{\circ }$. Find the acceleration in a mass of 8 g, which moves in a horizontal direction.

• A. 4 cm s${}^{-2}$
• B. 2 cm s${}^{-2}$
• C. 8 cm s${}^{-2}$
• D. 6 cm s${}^{-2}$

Answer 1

The correct option is A 4 cm s${}^{-2}$

Here, M $=$ 8 g
F $=$ 64 dyne (at an $\angle$60${}^{\circ }$ with the horizontal)
Therefore, component of the force along the horizontal,
$F_x=Fcos{60}^{\circ }=64\times \frac{1}{2}=32dyne$
If a is acceleration along the horizontal then
$F_x=Ma$ (or)
$a=\frac{F_x}{M}=\frac{32}{8}=4cm{s}^{-2}$